A Pakistani infant has undergone a life-saving surgery in the United States after a stranger paid for his travel expenses, reported the Daily Mail on Tuesday.

The 20-month old infant, Ibtisam Faisal, was suffering from hydrocephalus after his birth ? causing his skull to swell to 73 cm.

The condition also made the infant unable to sleep with his eyes closed, move freely and confined him to bed.

Local doctors had told the family of the infant in August that his only chance of survival was treatment abroad.

Faisal?s family campaigned for months for help in raising the funds till an anonymous caller offered to fly the ailing infant and his mother to Dallas for treatment by a leading surgeon in March.

Faisal underwent two successful brain surgeries, helping to reduce the size of his head to 63cm. Experts have expressed hope that more operations in the coming months will allow the infant to sit up and enjoy a normal life.

'It's hard for any parent to see their baby growing up unable to do anything but lay on a bed,? said Faisal?s mother.